I'll be breaking up my predictions into platform specific (Nintendo, Microsoft, and Sony), along with a post dedicated to third-parties. I don't have a schedule, but expect all four posts to be published before E3's start. Check out the hub for other prediction posts as they're published.
First things first, Sony is riding high into this year's E3, still rolling off of success after success. Their head is high, their horse is brushed pristinely, but it's going to be fairly easy for them to stumble this year; last year's E3 was a high point in the house of PlayStation.
Since launch, the PlayStation 4 has outsold the Xbox One month after month, even during March when Titanfall launched. They launched Infamous: Second Son to very solid reviews (and even better sales, even though it's here in software sales that Titanfall won), they have the - purported - best version of Watch Dogs to play, The Last of Us: Remastered is up for a summer release - as is PlayStation Now - and it's only May.